The concept of pre- and postjunctionally located α adrenoceptors, as well as the more recent subdivision into α1 and α2 subtypes, has initiated during the last decade a renaissance of interest in this class of receptors and in the drugs interfering with them. This interest has been further stimulated by the detection of previously unknown locations and functions of α adrenoceptors, the availability of new techniques, such as radioligand binding, and the increased knowledge of the processes linking α adrenoceptor activation to the pharmacological effect. In this paper, emphasis is directed toward α adrenoceptors that are presently classified as α2. The discovery of this type prompted the application of a nomenclature for α adrenoceptors. The functional relevance of α2 adrenoceptors is still growing. They are probably of high physiological significance and already serve as targets for various therapeutically useful drugs.